1. Field of the Invention
The invention relates to a module unit for memory modules and to a method for producing the module unit.
Because of the increasing volume of data used by data processing systems and the limited space availability, the problem of storing extensive data for computing operations in limited spaces is becoming increasingly greater. It consequently appears to be necessary to further increase the density of memory modules in module units. However, increasing the density of memory modules in module units is limited by the available module area and also by the required area per individual component. In addition, the number of individual components per module in a module unit is likewise limited.
2. Summary of the Invention
It is accordingly an object of the invention to provide a module unit and a method for producing the module unit such that the limit on the storage capacity of the module unit is eliminated.
It is an additional object of the invention to provide a module unit principle that permits improved space utilization and that permits the storage capacity to be expanded to any desired extent.
With the foregoing and other objects in view there is provided, in accordance with the invention, a module unit, including: a plurality of memory modules including at least one main module and a plurality of submodules; and a central inner plug connector formed with radially aligned slots. The main module has opposing sides, an external outer contact strip, and an inner contact strip. The inner contact strip is configured in one of the radially aligned slots of the central inner plug connector. The plurality of the submodules is aligned in a star-shaped, radially aligned manner around the central inner plug connector. Each one of the plurality of the submodules has an end with a contact strip configured in a respective one of the radially aligned slots of the central inner plug connector.
This module unit has the advantage that, with the central inner plug connector, all of the submodules are connected to the main module by the shortest path. A close arrangement is obtained in this region and the lengths of the interconnects from the main module to the submodules are the same for each of the submodules. The main module may in this case include the entire evaluation logic or only part of it. The individual submodules may be assigned a wide variety of functions by providing the modules with components of a wide variety of forms. For instance, logic functions, memory functions or radio-frequency processing functions can be performed by correspondingly configuring the modules and by using the short and constant lengths of the interconnects between the main module and the submodules. Instead of submodules, submodule arrangements or units which have the same star-shaped and radial arrangement as the module unit may also be arranged in the slots of the central plug connector.
In the case of the inventive configuration of the module unit, the third dimension is used in an advantageous way to provide an arrangement of memory modules that is as dense as possible and that is nevertheless unlimited in a module arrangement. In this case, the radial arrangement around a central plug-in device is an effective solution, especially since short connecting lines with a high packing density can be achieved by the invention.
U.S. Pat. No. 5,812,797 shows a star-shaped arrangement of circuit boards (PCBs) that carry submodules of smaller dimensions. However, no central plug-in device is provided, and this leads to longer connecting lines.
The radial arrangement of individual elements in relation to a center is represented in U.S. Pat. No. 5,251,097. This concerns equipment cabinets in a computer installation, not memory modules.
U.S. Pat. No. 5,095,407 and U.S. Pat. No. 5,834,843 deal with placing chip modules against one another; a radially centered arrangement is not provided.
In a preferred embodiment of the invention, each memory module has at least one semiconductor chip. This semiconductor chip may be located on the same memory module as logic chips and radio-frequency chips or else passive components. It is advantageous if these components are configured using silicon planar technology, since the memory modules of the memory unit are then extremely flat and can be placed in the star-shaped arrangement in a space-saving manner.
A further embodiment of the invention provides that each memory module has a printed circuit board that is coated on both sides and that has semiconductor memory chips on both sides. This printed circuit board may have an edge region with a contact strip, and if it is the main module, one edge of the printed circuit board may have an outer contact strip that protrudes from the module board, and the other edge may have an inner contact strip that is arranged in one of the slots of the central plug connector.
In a further embodiment of the invention, the module unit has submodule units of the first, and second to nth orders. Submodule units of the first order can be attached at the locations of a submodule and have the same star-shaped structure of the module unit, but with smaller dimensions so that this star-shaped submodule unit fits into the slot of a submodule. Such a submodule unit of the first order can have submodules and/or additional submodule units of the second order, which can be introduced at slots of submodules in a submodule unit of the first order. In this way, as in a snowflake crystal structure, increasingly smaller submodule units of higher order can be inserted into the inventive module unit. Consequently, the advantage of a further increase in the module area with an increase in the storage density per module unit is possible with this embodiment of the invention.
In a further embodiment of the invention, eight slots are arranged in a distributed manner on the circumference of the central plug connector for memory modules or submodule units of the first order. One slot is provided for the main module. Such an embodiment of the invention has the advantage that an eight-pointed star with radially extending memory modules is formed. It is possible for half of the slots to be taken up by submodules or by submodule units that are adapted to the slot of a submodule. These form an eight-pointed star, but with smaller dimensions.
In a further embodiment of the invention, the module unit is packaged in a polymer molding compound forming a housing. This housing forms a cylinder having a lateral surface. The contact strip of the main module protrudes in the axial direction from this lateral surface. The radial construction provides optimum dissipation of the heat through the housing, which includes a polymer molding compound. This heat removal can be improved by using corresponding heat-conducting fillers, which may make up 50 to 80% of the volume of the polymer molding compound. In a further embodiment of the invention, tubular through-openings are arranged in the polymer molding compound between the memory modules parallel to the axial direction. In this embodiment of the invention, heat removal may take place by the chimney effect of the through-openings, if the cylindrical housing of a polymer molding compound is arranged vertically upright with the end faces left exposed.
In a further embodiment of the invention, the housing is not produced from plastic, but from a cylindrical tube in which the module unit is fastened. In this form of housing, in addition to the pure chimney effect, active cooling may also be carried out in the tubular housing by a cooling air stream that is produced by a cooling fan. In such an embodiment of the invention, the advantages of a star-shaped and radial construction are obvious, since uniform and intensive cooling is achieved.
For positioning the main module, the housing with the cylindrical tube may have a slit for receiving the outer contact strip of the main module. Furthermore, guide grooves may be provided in the inside wall of the tubular housing, in order to arrange the submodules in a star-shaped and radial manner in the tubular housing. The semiconductor chips provided for the main module, for the submodules and for the submodule units of the first to nth orders may be logic chips, memory chips, or radio-frequency chips. These chips are arranged on both sides of the printed circuit board of the respective main module, submodule, or on the printed circuit boards of the submodule units of the first to nth orders. Consequently, the module unit has a high degree of flexibility, not only in the sizes of the memory modules, but also in the storage density and in the type of components, which are beneficial for a wide variety of application purposes.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method for producing a module unit. The method includes steps of:
producing a central plug connector having a circumference with slots distributed therein for contact strips of memory modules; providing at least one main module having an edge with an outer contact strip and an opposing edge with an inner contact strip; inserting the inner contact strip into one of the slots of the central plug connector so that the main module protrudes radially from the central plug connector; inserting submodules or submodule units into respective ones of the slots of the central plug connector; aligning the main module and the components in a star-shaped and radial manner; and packaging the main module, the components, and the central plug connector in a housing so that the outer contact strip of the main module protrudes from the housing.
This method advantageously has a relatively simple unit assembly, once the central plug connector has been produced. This is because the central plug connector has slots distributed on its circumference and the contact strips of the different memory modules can be inserted into these slots. Furthermore, the method is extremely variable, since both submodules and submodule units can be positioned in the slots. Finally, the method enables a simple and easily realizable housing to be formed. The basic cylindrical housing can be realized with polymer compounds by using relatively simple pressure molding processes.
For example, the module unit can be packaged into a housing by using an injection-molding technique. The module unit is embedded in a polymer molding compound, leaving the outer contact strip of the main module exposed. A further example includes forming elongate tubular, axially parallel through-openings in the polymer molding compound during packaging. This measure too, which serves substantially for improving the cooling of the module unit, can be realized with relatively inexpensive means.
In a further step of the method for producing the module unit, a cooling fan can be attached to one of the ends of the housing that has through-openings in the polymer molding compound. Active cooling provided by the air stream of the fan can then improve the cooling intensity. Furthermore, after producing through-openings from one end to the other, active cooling by liquids is also possible.
The module unit may also be packaged in a tubular housing. The end of the tubular housing remains open. A cooling fan may be provided on one end of the housing to intensify the cooling of the module unit. A cylindrical housing of this type, which receives the central plug connector and the radially aligned modules, may be produced from a plastic tube or a metal tube. For this application, the plastic tube may consist of a fiber-reinforced epoxy resin. A metal tube housing may be produced from aluminum, copper or brass and may additionally have cooling ribs which are outwardly directed or arranged on the inside wall.
To sum up, it can be stated that high-density memory modules are limited by two factors; on the one hand by the available module area, and on the other hand by the area required for individual components. Consequently, the number of individual components per module is limited. According to the invention, the available module area is now increased by the best possible volume utilization, and the electrical properties of the overall system are improved. Consequently, stacked packages can be used to obtain a component level with third dimension, and the module area is also increased. At the same time, relatively short interconnects between the main module and the submodule are achieved. This produces a dense arrangement. The radial arrangement is the most effective way of achieving a high packing density and short interconnects. Accordingly, the invention arranges a plurality of submodules around a main module. A central plug connector provides the connection from one printed circuit board to the other printed circuit board of the memory module in a very restricted space. In this case, the lengths of the interconnects from the main module to the submodules are all the same. The main module may include the entire evaluation logic or else only parts of it, and the individual submodules may be assigned a wide variety of tasks. Furthermore, the radial arrangement can be constantly repeated in the case of corresponding submodule units.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a module unit for memory modules and method for its production, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.